package org.smart4j.framework.util;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileFilter;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/**
 * Created by Administrator on 2016/9/20.
 */
public final class ClassUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(ClassUtil.class);

    /**
     * 获取类加载器
     * @return
     */
    public static ClassLoader getClassLoader(){
        return Thread.currentThread().getContextClassLoader();
    }

    /**
     * 加载类
     * @param className
     * @param isInitialized
     * @return
     */
    public static Class<?> loadClass(String className,boolean isInitialized){
        Class<?> cls;
        try {
            cls = Class.forName(className,isInitialized,getClassLoader());
        }catch (ClassNotFoundException e){
            LOGGER.error("load class failure",e);
            throw new RuntimeException(e);
        }
        return cls;
    }
    public static Class<?> loadClass(String className){
        Class<?> cls;
        try {
            cls = Class.forName(className,false,getClassLoader());
        }catch (ClassNotFoundException e){
            LOGGER.error("load class failure",e);
            throw new RuntimeException(e);
        }
        return cls;
    }

    /**
     * 获取指定包名下的所有类
     * @param packageName
     * @return
     */
    public static Set<Class<?>> getClassSet(String packageName){
        Set<Class<?>> classSet = new HashSet<Class<?>>();
        try {
            Enumeration<URL> urls = getClassLoader().getResources(packageName.replace(".","/"));
            while (urls.hasMoreElements()){
                URL url = urls.nextElement();
                if(url != null){
                    String protocol = url.getProtocol();//获取资源类型
                    if("file".equals(protocol)){
                        String packagePath = url.getPath().replaceAll("%20","");
                        addClass(classSet,packagePath,packageName);
                    }else if("jar".equals(protocol)){
                        JarURLConnection jarURLConnection = (JarURLConnection) url.openConnection();
                        if(jarURLConnection != null){
                            JarFile jarFile = jarURLConnection.getJarFile();
                            if(jarFile != null){
                                Enumeration<JarEntry> jarEntries= jarFile.entries();
                                while (jarEntries.hasMoreElements()){
                                    JarEntry jarEntry = jarEntries.nextElement();
                                    String jarEntryName = jarEntry.getName();
                                    if(jarEntryName.endsWith(".class")){
                                        String className = jarEntryName.substring(0,jarEntryName.lastIndexOf(".")).replace("/",".");
                                        doAddClass(classSet,className);
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }catch (Exception e){
            LOGGER.error(" get class set failure",e);
            throw new RuntimeException(e);
        }
        return classSet;
    }

    private static void addClass(Set<Class<?>> classSet, String packagePath, final String packageName) {
        final File [] files = new File(packagePath).listFiles(new FileFilter() {
            @Override
            public boolean accept(File pathname) {
                return (pathname.isFile() && pathname.getName().endsWith(".class") || pathname.isDirectory());
            }
        });
        for(File file : files){
            String fileName = file.getName();
            if(file.isFile()){
                String className = fileName.substring(0,fileName.lastIndexOf("."));
                if(StringUtils.isNotEmpty(packageName)){
                    className = packageName + "." + className;
                }
                doAddClass(classSet,className);
            }else{
                String subPackagePath = fileName;
                if(StringUtils.isNotEmpty(packagePath)){
                    subPackagePath = packagePath + "/" + subPackagePath;
                }
                String subPackageName = fileName;
                if(StringUtils.isNotEmpty(packageName)){
                    subPackageName = packageName + "." + subPackageName;
                }
                addClass(classSet,subPackagePath,subPackageName);
            }
        }
    }

    private static void doAddClass(Set<Class<?>> classSet, String className) {
        Class<?> cls = loadClass(className, false);
        classSet.add(cls);

    }
}
